Piping systems exist to facilitate the flow of fluids (e.g., liquid, steam, gas (such as air) or plasma). For example, homes, schools, medical facilities, commercial buildings and other occupied structures generally require integrated piping systems so that water and/or other fluids can be circulated for a variety of uses. Liquids and/or gases such as cold and hot water, breathable air, glycol, compressed air, inert gases, cleaning chemicals, waste water, plant cooling water and paint and coatings are just some examples of the types of fluids and gases that can be deployed through piping systems. Tubing and piping types can include, for example, copper, stainless steel, CPVC; (chlorinated polyvinyl chloride) and PEX (cross-linked polyethylene). For purposes of the present disclosure, the term “pipe” or “piping” will be understood to encompass one or more pipes, tubes, piping elements and/or tubing elements.
Piping connections are necessary to join various pieces of pipe and must be versatile in order to adapt to changes of pipe direction required in particular piping system implementations. For example, fittings and valves may be employed at the ends of open pieces of pipe that enable two pieces of pipe to fit together in a particular configuration. Among fitting types there are elbows, “tees”, couplings adapted for various purposes such as pipe size changes, ends, ball valves, stop valves, and partial angle connectors, for example.
In the past, pipe elements have been traditionally connected by welding and/or soldering them together using a torch. Soldering pipe fittings can be time-consuming, unsafe, and labor intensive. Soldering also requires employing numerous materials, such as copper pipes and fittings, emery cloths or pipe-cleaning brushes, flux, silver solder, a soldering torch and striker, a tubing cutter and safety glasses, for example. The process for soldering pipes can proceed by first preparing the pipe to be soldered, as the copper surface must be clean in order to form a good joint. The end of the pipe can be cleaned on the outside with emery cloth or a specially made wire brush. The inside of the fitting must be cleaned as well. Next, flux (a type of paste) can be applied to remove oxides and draw molten solder into the joint where the surfaces will be joined. The brush can be used to coat the inside of the fitting and the outside of the pipe with the flux. Next, the two pipes are pushed together firmly into place so that they “bottom out”—i.e., meet flush inside the fitting. The tip of the solder can be bent to the size of the pipe in order to avoid over-soldering. With the pipes and fitting in place, the torch is then ignited with the striker or by an auto-strike mechanism to initiate soldering. After heating for a few moments, if the copper surface is hot enough such that it melts when touched by the end of the solder, the solder can then be applied to the joint seam so that it runs around the joint and bonds the pipe and fitting together.
In addition to welding methods, pipe elements have been secured together through pressure. A press fitting, which is also known as a friction fit or an interference fit, is a fastening of parts that takes place through friction after the parts are pushed or compressed together, as opposed to being connected by threads, glue, solder or other methods. Press fittings of fluid flow parts such as plumbing parts can be created by force, through the use of a hand tool, for example. Hand tools, often called press tools, can take the form of a pair of movably engaged jaws similar to a pair of pliers, for example, where the jaws have a head portion of a certain size designed to fit around parts that are to be connected. For instance, a pipe can be inserted into a fitting made of a somewhat compressible material, whereupon pressure can be applied through the press tool to the outside of the fitting in order to compress the fitting around the pipe. It is critical that the press tool be appropriately applied around the entire circumference of the fitting in order to ensure a tight connection. Once connected, the parts can be used for various purposes. In the field of fluid flow, the connected parts can be used to direct the flow of fluids, such as gases, water and other liquids as described above.
Traditional press fittings are frequently improperly sealed or only partially sealed. If an installer has not properly pressed the fitting to provide a permanent seal, fluid can leak, causing great damage and cost. Imperfections or scarring in the tubing being inserted also presents an opportunity for the connection to leak following compression. In many installation environments, installers take work breaks or otherwise become distracted as to which of a number of press fittings have been properly compressed and which have been either improperly compressed or not at all. When this happens, there has been no simple and fast way (other than catastrophic failure or leakage) to determine which fittings have been properly pressed, which can result in lost time spent determining which fittings need to be pressed or in damage in the application environment.
The present invention, in part, assists in providing one or more visual indicators to assist an individual in determining whether a piping element such as a fitting has been pressed, and whether the correct amount of force has been applied to create a positive and/or permanent seal. For purposes of the present disclosure, it will be appreciated that a fitting can encompass a valve member and other piping elements including, but not limited to: a coupling joint, an elbow joint, a tee joint, a stop end, a ball valve member, tubing and other objects having cylindrical openings. In embodiments of the present invention, a fitting is provided having a main body component, with an interior indicator securely maintained against a portion of the interior wall of the main body component, and an exterior indicator securely maintained against a portion of the exterior wall of the main body component. The interior indicator (which can also be referred to as a membrane seal, indicator seal and/or indicator membrane, for example) is expandable when properly compressed so as to extend outside of the fitting around an inserted pipe. The external indicator is compressible so as to change color when proper pressure has been applied. In this way, an installer, inspector or other individual can visually determine very quickly whether a press fitting has been compressed, and whether there is a proper and complete seal. In various embodiments, the interior indicator has an inner lip that, when compressed, provides a secondary wiper seal that fills voids, scarring or imperfections in the tubing being inserted as well as in the fitting wall.